JP7579175B2 - Pump-type discharge device - Google Patents

Description

This invention relates to a pump-type discharge device that reduces the internal volume of a cylinder by pushing in a nozzle body, thereby discharging the contents pushed out of the cylinder from a nozzle formed in the nozzle body.

An example of a container equipped with this type of device is described in Patent Document 1. The device is mainly made of thermoplastic resin and is a pump former that foams and discharges liquid contents such as shampoo, hand soap, and body soap. In the device, an air cylinder is attached to the mouth of a bottle, and a liquid cylinder is integrally constructed on a concentric circle inside the air cylinder in the radial direction. The air piston that slides against the inner surface of the air cylinder and the liquid piston that slides against the inner surface of the liquid cylinder are arranged on a concentric circle and are integrated. A flow path is formed through the liquid piston, and the flow path is connected to a nozzle and a liquid chamber partitioned by the liquid cylinder and the liquid piston. In addition, a check valve is provided in the flow path, which communicates the nozzle and the liquid chamber when the liquid piston moves toward the bottle side and blocks the above-mentioned communication when the liquid piston moves to the opposite side. The check valve has a rod-shaped valve body extending in the axial direction, and the rod-shaped valve body is arranged in the above-mentioned flow path. A tapered valve body portion with an outer diameter gradually increasing toward the side opposite the bottle is formed at one end of the rod-shaped valve body opposite the bottle, and a funnel-shaped valve seat portion that comes into close contact with the valve body portion is formed at one end of the liquid cylinder opposite the bottle. A spring is also provided to move the liquid piston back to its original position. The elastic force of the spring presses the liquid piston toward the side opposite the bottle so that the valve seat portion and the valve body portion come into close contact with each other to close the check valve. The other end of the rod-shaped valve body is held in the liquid chamber so as to be movable relative to the liquid piston.

Patent No. 5435794

If the above-mentioned device is stored for a long period of time at high temperatures, the heat during storage may soften the valve seat and valve body, since the device is mainly made of thermoplastic resin. In that case, the valve seat and valve body may fit tightly together due to the elastic force of the spring, making it difficult to separate them from each other. Also, when the above-mentioned device is in an unused state, the liquid contents have not yet been sucked up into the liquid chamber, and air fills the liquid chamber. In this state, when the above-mentioned device is started to be used and the nozzle body is pressed down, the air piston and liquid piston are pressed down, and air is discharged from the nozzle body. In that case, the above-mentioned valve body and valve seat that open and close the liquid chamber are firmly fitted together, and the air in the liquid chamber is compressible, so that the rod-shaped valve body (valve body) is pressed down together with the liquid piston (valve seat), and the valve body and valve seat do not separate. In other words, the liquid chamber does not open. If the nozzle body is pressed further down or if the nozzle body is repeatedly pressed down (pumped), the air pressure in the liquid chamber repeatedly increases, causing the valve body and the valve seat to separate, and the contents in the bottle are drawn up into the liquid chamber. Thus, as described above, when the user first starts using the bottle, the valve body and the valve seat are engaged or not sufficiently separated, so the amount of contents drawn up into the liquid chamber is insufficient, and the nozzle body must be pressed down (pumped) multiple times until the amount of discharge from the nozzle body reaches the amount that is intended by the design, which can make the bottle less convenient to use at the beginning.

This invention was made with a focus on the above technical problems, and aims to provide a highly convenient pump-type discharge device that has a valve mechanism that opens easily when used for the first time after being stored at high temperatures in an unused state, making it easy to discharge the contents.

In order to achieve the above object, the present invention provides a bottle having a cylinder attached to a mouth portion of a bottle in a state of communication with the interior of the bottle, a piston fitted into the interior of the cylinder so as to be able to reciprocate in the axial direction of the cylinder, a flow path formed penetrating the piston in the axial direction, a nozzle communicating with one open end of the flow path, one of the interiors partitioned by the cylinder and the piston to which the other open end of the flow path is connected, a valve mechanism having a valve body portion and a valve seat portion which come into close contact with each other to close the flow path when the piston moves in a direction increasing the volume of the one interior, and which move apart from each other to open the flow path when the piston moves in a direction decreasing the volume of the one interior, and a return mechanism which presses the piston in a direction to press the valve body portion against the valve seat portion, a valve seat portion having a funnel-shaped outer peripheral surface that contacts the outer peripheral surface and closes the flow path, and when the piston is pushed, the valve body portion separates from the valve seat portion and the volume of the one of the interiors is reduced, thereby discharging the content filled in the one of the interiors from the nozzle through the flow path, wherein a convex curved surface portion having a center of curvature on the opposite side to the receiving surface side is formed continuously around the entire circumference in the circumferential direction of the flow path on the outer peripheral surface, and a contact portion between the convex curved surface portion and the receiving surface forms a continuous line around the entire circumference in the circumferential direction of the flow path, and further the valve body portion including the convex curved surface portion is made of a synthetic resin material harder than the synthetic resin material forming the valve seat portion including the receiving surface .

In the present invention, the valve body may be made of high-density polyethylene having a Rockwell hardness of 60 to 70, and the valve seat may be made of polypropylene having a Rockwell hardness of 85 to 110 or polyoxymethylene having a Rockwell hardness of 80 to 120 .

In this invention, a shaft-shaped member is provided, one end of which is inserted into the inside of the flow passage along the central axis of the flow passage, and the other end of which is disposed inside the one end and held so as to be movable relative to the cylinder in the axial direction, and the valve body portion is formed in a tapered shape at the one end of the shaft-shaped member with an outer diameter gradually increasing toward the opposite side of the bottle in the axial direction, and the valve seat portion is formed in a funnel shape inside the flow passage with an inner diameter gradually increasing toward the opposite side of the bottle in the axial direction, and the convex curved surface portion may be formed on the outer circumferential surface.

In this invention, a nozzle is connected to one of the interiors partitioned by the piston and the cylinder through a flow path. A valve mechanism is provided in the flow path, which opens the flow path when the piston moves to reduce the volume of one of the interiors, and closes the flow path when the piston moves to increase the volume of the one of the interiors. The valve mechanism has a valve body and a valve seat. The valve body has a tapered outer peripheral surface, and the valve seat has a funnel-shaped receiving surface facing the outer peripheral surface. The outer peripheral surface and the receiving surface are configured to receive a force in a direction in which they come into close contact with each other by a return mechanism, and the flow path is closed by the valve seat and the valve body. In this invention, at least one of the outer peripheral surface of the valve body and the receiving surface of the valve seat has a convex curved surface portion having a center of curvature on the opposite side to the other side, which is formed continuously around the entire circumference in the circumferential direction of the flow path. The convex curved surface portion comes into contact with the outer peripheral surface of the valve body or the receiving surface of the valve seat, resulting in a closed valve state. Therefore, the contact area between the valve body and the valve seat is smaller than that in the case where the outer circumferential surface and the receiving surface are in contact with each other over the entire surface, and therefore the frictional force between the valve body and the valve seat and the engagement force between them are reduced more than ever before. Therefore, according to this invention, the engagement state between the outer circumferential surface of the valve body and the receiving surface of the valve seat can be released with a relatively small force. Specifically, for example, even if one of the interiors is filled with air, which is a compressible fluid, and the force pushing the piston to reduce the volume of the one of the interiors is consumed and reduced by compressing the air, the valve body and the valve seat can be easily separated by the increase in internal pressure of the one of the interiors due to the compression of the air. In other words, the valve body and the valve seat can be easily separated by a slight increase in internal pressure. Therefore, by storing the pump-type discharge device according to the embodiment of the present invention at a high temperature for a long period of time, the valve seats fit tightly together, and even if one of the seats is filled with air and the piston reciprocates repeatedly to open the valve mechanism, the number of reciprocating movements of the piston, i.e., the number of pumping operations, can be reduced as much as possible. As a result, according to this invention, even when an unused pump-type discharge device is used for the first time after being stored at a high temperature for a relatively long period of time, the liquid contents can be quickly and sufficiently sucked up, and the number of pumping operations required to discharge the required amount from the nozzle can be reduced, improving convenience.

1 is a cross-sectional view showing an example of a pump-type discharge device according to an embodiment of the present invention. FIG. 2 is an enlarged cross-sectional view showing a portion of the valve mechanism according to the embodiment of the present invention. FIG. 3A is a diagram showing a state in which the liquid piston is positioned at top dead center, and FIG. 3B is a diagram showing a state in which the liquid piston is pushed into the bottle and the valve body portion and the valve seat portion are separated.

Figure 1 is a cross-sectional view showing an example of a pump-type discharge device according to an embodiment of the present invention. The pump-type discharge device shown in Figure 1 is a so-called pump former 1, which is configured to mix the liquid contents filled inside a bottle 2 with air to form foam and discharge the foam. That is, the pump former 1 shown in Figure 1 has a cap 4 that is removably attached to the mouth 3 of the bottle 2. The mouth 3 is a cylindrical opening formed on the upper end side of the body of the bottle 2, and a male thread is formed on the outer periphery of the mouth 3. A female thread that fits into the male thread is formed on the cap 4. In other words, the mouth 3 is screwed onto the cap 4.

As shown in FIG. 1, the cap 4 has an outer cylindrical portion 5 with an outer diameter larger than the outer diameter of the mouth portion 3, and an inner cylindrical portion 6 arranged concentrically with the outer cylindrical portion 5 inside the outer cylindrical portion 5. The inner cylindrical portion 6 has an outer diameter smaller than the inner diameter of the mouth portion 3 and is set to have a length in the axial direction shorter than that of the outer cylindrical portion 5. The upper end of the outer cylindrical portion 5 and the upper end of the inner cylindrical portion 6 are connected by an upper surface portion 7 extending in the radial direction. In other words, the outer cylindrical portion 5, the inner cylindrical portion 6, and the upper surface portion 7 are formed integrally. In addition, the above-mentioned female thread is formed on the inner peripheral surface of the outer cylindrical portion 5. An opening with an inner diameter smaller than the inner diameter of the inner cylindrical portion 6 is formed in the center of the upper surface portion 7. A cylindrical guide stem portion 8 extending upward in FIG. 1 is erected on the periphery of the opening. A nozzle body 9 that pumps the pump former 1 is fitted into the guide stem portion 8 so as to be slidable in the axial direction (up and down direction in FIG. 1).

The nozzle body 9 has a top surface 10 to which a downward force is applied as a so-called nozzle head, a nozzle 11 that ejects foam, a cylindrical inner tube 12 in which a flow path P communicating with the nozzle 11 is formed, and a cylindrical outer tube 13 that is larger in diameter than the inner tube 12 and is formed concentrically with the inner tube 12. A part of the nozzle body 9 is cylindrical and extends outward in the radial direction centered on the axis of the nozzle body 9, and this part forms the nozzle 11. Each tube 12, 13 extends downward in the axial direction from the top surface 10 of the nozzle body 9 in FIG. 1, and the length of the inner tube 12 in the axial direction is set to be longer than the outer tube 13. The outer diameter of the inner tube 12 is set slightly smaller than the inner diameter of the guide stem 8, so that it can be inserted inside the guide stem 8. The inner diameter of the outer tube 13 is set slightly larger than the outer diameter of the guide stem 8, so that the guide stem 8 can be inserted inside it. In other words, by inserting the guide stem portion 8 between the inner cylinder portion 12 and the outer cylinder portion 13 in the radial direction, the nozzle body 9 is guided by the guide stem portion 8 and each cylinder portion 12, 13 to move in the axial direction. In addition, small gaps are formed between the outer peripheral surface of the inner cylinder portion 12 and the inner peripheral surface of the guide stem portion 8, and between the outer peripheral surface of the guide stem portion 8 and the inner peripheral surface of the outer cylinder portion 13, and these gaps serve as air flow paths. Air is introduced into the air cylinder described below through these air flow paths.

In the example shown in FIG. 1, a net holder 14 that forms a homogeneous foam is fitted to the inner peripheral surface of the inner tube 12. Specifically, the net holder 14 is a cylindrical member, and a net (not shown) is attached to each of both ends in the axial direction. The inner diameter of the inner tube 12 is slightly larger on the side opposite the top surface 10 across the central portion in the axial direction, and the above-mentioned net holder 14 is fitted into this part with the larger inner diameter. Then, as described below, the contents that have been whipped by mixing with air pass through the net holder 14, forming fine, homogeneous foam.

A cylinder 15 is disposed inside the cap 4. As shown in FIG. 1, the cylinder 15 is fitted to the outer periphery of the inner cylindrical portion 6 and integrated with the cap 4, and the inner diameter of the lower portion is slightly smaller than the fitting portion that fits into the inner cylindrical portion 6. In addition, a flange 16 that extends outward in the radial direction is formed at the upper end of the cylinder 15. The outer diameter of the flange 16 is approximately the outer diameter of the tip of the mouth portion 3 (the outer diameter of the opening of the mouth portion 3) or slightly larger. A sealant 17 is sandwiched between the tip (opening end) of the mouth portion 3 and the lower surface of the flange 16 (the lower surface of the flange 16 in FIG. 1) to ensure airtightness and liquid tightness. The flange 16 and the sealant 17 are sandwiched between the upper surface portion 7 of the cap 4 and the tip of the mouth portion 3 by attaching the cap 4 to the mouth portion 3 with a screw, and seal the mouth portion 3.

To explain the configuration of the cylinder 15 in detail, the cylinder 15 shown here is integrally formed with an air cylinder 18 of an air pump that pushes air into the nozzle body 9 and a liquid cylinder 19 of a liquid pump that pushes the contents into the nozzle body 9. The air cylinder 18 is a large-diameter part of the cylinder 15 formed below the above-mentioned fitting part in the axial direction, and a first intake hole 20 for taking air into the inside of the bottle 2 is formed in a part of the upper end side of the air cylinder 18, penetrating the plate thickness direction of the air cylinder 18. The liquid cylinder 19 is formed in a cylindrical shape with a smaller diameter than the air cylinder 18, and is formed concentrically with the air cylinder 18. Also, as shown in FIG. 1, a part of the liquid cylinder 19 is formed inside the air cylinder 18 in the radial direction. In other words, the liquid cylinder 19 and the air cylinder 18 are formed slightly offset in the axial direction, and at least a part of them overlap each other in the radial direction. In the example shown here, the liquid cylinder 19 is formed continuously with the air cylinder 18. The boundary between these cylinders 18, 19 is a convex curved portion formed by curving the bottom of the air cylinder 18 so that it protrudes upward in FIG. 1, and the flange of the liquid piston described below comes into contact with this boundary portion, preventing further movement (pushing) of the nozzle body 9 and each piston. This position is the stroke end, or bottom dead center, of the nozzle body 9 and each piston when each piston is pushed toward the bottle 2. Note that the example shown in FIG. 1 shows the state in which the nozzle body 9 is at top dead center.

An air piston 21 that slides in the axial direction (up and down direction in FIG. 1) while maintaining an airtight state is fitted to the inner peripheral surface of the air cylinder 18. The air pump is composed of the air cylinder 18 and the air piston 21. The air piston 21 has a piston head 22 that divides the inside of the air cylinder 18 into upper and lower parts in FIG. 1, and a sliding part 23 that is integrated with the piston head 22 and contacts the inner peripheral surface of the air cylinder 18. Of the two interiors divided by the piston head 22, the interior below the piston head 22 in FIG. 1 is the air chamber 24. In the example shown in FIG. 1, the sliding part 23 is formed in a cylindrical shape, and is configured to slidably contact the inner peripheral surface of the air cylinder 18 at two points, the upper and lower parts, while maintaining airtightness. The sliding part 23 reciprocates in the axial direction to open and close the first air intake hole 20.

At a predetermined radial position on the piston head 22 in the radial direction, a second intake hole 25 is formed penetrating the piston head 22 in the plate thickness direction to introduce air into the air chamber 24. In addition, a molding valve 26 is attached to the piston head 22 in the radial direction inward of the second intake hole 25, which connects the air chamber 24 to the outside of the bottle 2 depending on the internal pressure of the air chamber 24, and also connects the air chamber 24 to a mixing chamber, which will be described later.

The molding valve 26 includes a cylindrical shaft portion fitted into a recess formed in the piston head 22, an annular outer valve portion extending radially outward from the end of the shaft portion exposed from the recess, and an annular inner valve portion extending radially inward from the end of the shaft portion exposed from the recess. The outer valve portion covers the second intake hole 25 from the inside of the air chamber 24 so as to close the second intake hole 25 when the internal pressure of the air chamber 24 increases above the pressure outside the bottle 2, and to open the second intake hole 25 when the internal pressure of the air chamber 24 decreases below the pressure outside the bottle 2. In other words, the outer valve portion constitutes an air intake valve 27 that introduces or blocks outside air into the air chamber 24. The inner valve portion is in contact with the flange of the liquid piston described later so as to communicate the air chamber 24 with the mixing chamber when the internal pressure is higher than the pressure outside the bottle 2, and to block the communication between the air chamber 24 and the mixing chamber when the internal pressure decreases below the pressure outside the bottle 2. In other words, the inner valve portion forms an air exhaust valve 28 that supplies or pushes air from the air chamber 24 to the mixing chamber.

In addition, a cylindrical portion 29 is integrally formed at the center of the piston head 22 in the radial direction, extending toward the opposite side to the bottle 2 (upper side in FIG. 1). The inner tube portion 12 formed in the nozzle body 9 described above is fitted into one end of the cylindrical portion 29 (upper end in FIG. 1), and the lower end of the net holder 14 is fitted into it. In the example shown in FIG. 1, a convex rib portion is formed on the outer peripheral surface of one end of the cylindrical portion 29, and a concave groove portion that fits into the convex rib portion is formed on the inner peripheral surface of the inner tube portion 12. The fitting of these convex rib portions and concave groove portions firmly connects the cylindrical portion 29 and the inner tube portion 12. The cylindrical portion 29 and the inner tube portion 12 may be connected by means of a screw fit or a snap fit.

The inner diameter of one end of the cylindrical portion 29 is formed slightly larger than the outer diameter of the lower end of the net holder 14. In addition, one or more protrusions 30 protruding inward in the radial direction are formed on the inner peripheral surface of the lower side of the part of the larger inner diameter of one end of the cylindrical portion 29. The protrusions 30 contact one end of the shaft-shaped member described later and push the shaft-shaped member when the nozzle body 9 is pushed in. Furthermore, the inner diameter of the protrusions 30 is set to be approximately the inner diameter of the net holder 14 so as not to particularly hinder the flow of the contents in the flow path P. Then, as shown in FIG. 1, when the nozzle body 9 is at the top dead center position, a clearance C is set between the upper end of the valve body part of the shaft-shaped member described later and the side of the protrusion 30 that contacts the upper end. The lower end of the net holder 14 is fitted into the fitting portion formed by the part of the larger inner diameter of one end of the cylindrical portion 29 described above and the protrusions 30. In this way, the air piston 21 and the nozzle body 9 are integrated, and the net holder 14 is held in the flow path P between them. Therefore, when the top surface 10 of the nozzle body 9 is pressed toward the bottle 2 to push the nozzle body 9 down, the air piston 21 moves toward the bottle 2 together with the nozzle body 9, and the volume of the air chamber 24 partitioned by the air cylinder 18 and the air piston 21 decreases. Then, the inside of the air chamber 24 is pressurized, and the air inside the air chamber 24 is pushed out of the air chamber 24. In addition, when the air piston 21 is pushed down toward the bottle 2 by the amount of the above-mentioned clearance C, the protrusion 30 comes into contact with the upper end of the valve body of the shaft-shaped member and pushes the shaft-shaped member down toward the bottle 2.

The liquid piston 31 of the liquid pump is fitted to the other end (lower end in FIG. 1) of the cylindrical portion 29. As shown in FIG. 1, the liquid piston 31 is formed in a cylindrical shape extending in the axial direction, and one end (upper end in FIG. 1) of the liquid piston 31 is fitted to the other end of the cylindrical portion 29. Specifically, a recess is formed in the other end of the cylindrical portion 29, recessed in the axial direction into which one end of the liquid piston 31 fits. The inner diameter of the recess is set to an inner diameter such that one end of the liquid piston 31 fits. In addition, an air flow path (not shown) is formed between the recess and one end of the liquid piston 31. The space between the fitting portion between the other end of the cylindrical portion 29 and the liquid piston 31 in the axial direction and the net holder 14 fitted inside the cylindrical portion 29 is the mixing chamber 32 in which the air and the liquid contents are mixed. One end of the air flow path described above is connected to the flow path P in the cylindrical portion 29 described above, and the other end is connected to the space partitioned by the liquid piston 31 and the air piston 21.

A flange 33 that protrudes outward in the radial direction is formed on the outer peripheral surface of the liquid piston 31. As described above, the flange 33 defines the lower limit positions of the air piston 21 and the liquid piston 31. Also, as shown in FIG. 1, when the nozzle body 9 is at the top dead center, the air exhaust valve 28 contacts the upper surface of the flange 33. The other end of the liquid piston 31 is fitted to the inner peripheral surface of the liquid cylinder 19 so as to slide in the axial direction (up and down direction in FIG. 1) while maintaining a liquid-tight state. Therefore, the liquid pump described above is constituted by the liquid cylinder 19 and the liquid piston 31, and the cylindrical space formed by the liquid cylinder 19 and the liquid piston 31 is the liquid chamber 34. As described above, when the top surface portion 10 of the nozzle body 9 is pressed toward the bottle 2 to press down the nozzle body 9, the liquid piston 31 moves toward the bottle 2 together with the air piston 21, and the volume of the liquid chamber 34 described above decreases. The interior of the liquid chamber 34 is pressurized, and the liquid inside the liquid chamber 34 is pushed out of the liquid chamber 34. The above-mentioned liquid chamber 34 corresponds to one of the interiors in this embodiment of the invention.

Inside the liquid chamber 34, there are disposed a return mechanism that returns the nozzle body 9 and each piston to their original positions when the force pushing the nozzle body 9 and each piston toward the bottle 2 side is released, and a valve mechanism that connects the liquid chamber 34 to the inside of the bottle 2 in response to pumping of the nozzle body 9 and also connects the liquid chamber 34 to the mixing chamber 32 and the flow path P. First, the return mechanism will be described. In the embodiment shown here, the return mechanism is configured to return the nozzle body 9 and each piston 21, 31 by the elastic force of a coil spring (hereinafter simply referred to as a spring) 35. A spring receiving portion that fits one end of the spring 35 is formed on the other end of the liquid piston 31 described above, and a similar spring receiving portion is provided on the inner periphery of the bottom of the liquid cylinder 19. The spring 35 is disposed between these spring receiving portions in a compressed state. Therefore, an elastic force that pushes the liquid piston 31 upward toward the opposite side to the bottle 2 side (upper side in FIG. 1) is constantly acting on the liquid piston 31.

The valve mechanism is a check valve that opens when the contents are pushed out of the liquid chamber 34 and closes when the contents are sucked up from the inside of the bottle 2 into the inside of the liquid chamber 34 to fill it. FIG. 2 is a cross-sectional view showing an enlarged portion of the valve mechanism. As shown in FIG. 2, an axial member 36 is arranged along the central axis of the liquid cylinder 19. One end of the axial member 36 protrudes from one end of the liquid piston 31. A valve body portion 37 is integrally formed with one end of the axial member 36. The valve body portion 37 is tapered in such a way that the outer diameter gradually increases toward the one end of the axial member 36 opposite the bottle 2. In the example shown in FIG. 2, the outer peripheral surface 37A of the tapered valve body portion 37 has a center of curvature on the central axis side of the flow path P, and a convex curved surface portion 37B with a cross section of an arc shape that protrudes outward in the radial direction of the flow path P is formed continuously around the entire circumference.

On the other hand, an annular convex portion is formed at one end of the liquid piston 31, protruding radially inward, that is, toward the central axis of the flow path P. The annular convex portion is located closer to the bottle 2 than the valve body portion 37 in the axial direction, and its minimum inner diameter is set to be smaller than the outer diameter of the valve body portion 37 so that it fits closely or engages with the convex curved surface portion 37B of the valve body portion 37. Specifically, the upper surface of the annular convex portion (the surface facing the tapered surface of the valve body portion 37) is formed in a funnel shape following the outer shape of the outer peripheral surface 37A of the valve body portion 37 so that the inner diameter gradually increases upward in FIG. 2. Therefore, the upper surface 38A of this annular convex portion is configured to contact the convex curved surface portion 37B of the valve body portion 37 from the lower side in FIG. 2 to close the flow path P and the liquid chamber 34 in a liquid-tight state. In other words, the annular convex portion serves as the valve seat portion 38. In addition, by doing so, the contact area between the convex curved surface portion 37B and the upper surface 38A is a continuous linear contact surface around the entire circumference in the circumferential direction. In addition, the contact area is reduced compared to when the tapered outer peripheral surface 37A of the valve body portion 37 and the upper surface 38A of the valve seat portion 38 are in contact with each other. In this way, the valve mechanism 39 described above is formed by the valve body portion 37 and the valve seat portion 38.

The tapered outer peripheral surface 37A of the valve body portion 37 corresponds to the outer peripheral surface of the valve body portion in this embodiment of the invention, and the convex curved surface portion 37B corresponds to the convex curved surface portion of the valve body portion in this embodiment of the invention. The valve seat portion 38 corresponds to the valve seat portion in this embodiment of the invention, and the funnel-shaped upper surface 38A of the valve seat portion 38 corresponds to the receiving surface of the valve seat portion in this embodiment of the invention. Therefore, the valve mechanism 39 formed by the above-mentioned valve body portion 37 and valve seat portion 38 corresponds to the valve mechanism in this embodiment of the invention.

Returning to FIG. 1, to further explain the pump former 1, the other end (the lower end in FIG. 1) of the shaft-shaped member 36 opposite the valve body portion 37 has a downward arrowhead shape or a triangular cross section, as shown in FIG. 1. The other end is inserted into the inside of a cylindrical locking body 40 provided at the bottom of the liquid cylinder 19, and is in contact with the inner peripheral surface of the locking body 40, and in this state slides on the inner peripheral surface of the locking body 40. More specifically, the outer diameter of the lower end of the shaft-shaped member 36 is set slightly larger than the inner diameter of the inner peripheral surface of the locking body 40, and is elastically deformed to reduce the outer diameter when inserted into the inside of the locking body 40. In other words, an elastic force is generated at the other end of the shaft-shaped member 36 such that its outer circumferential surface contacts the inner circumferential surface of the locking body 40, and when no load is acting on the shaft-shaped member 36 to move it in the axial direction, the elastic force and the frictional force between the inner circumferential surface of the locking body 40 and the other end of the shaft-shaped member 36 prevent it from moving in the axial direction. In other words, the other end of the shaft-shaped member 36 serves as an engagement portion 41 for the locking body 40.

The inner periphery of one end of the locking body 40 (the upper end in FIG. 1) is formed in the above-mentioned arrowhead shape or triangular cross section, and forms a hook portion 42 that hooks onto the jaw portion of the engagement portion 41 of the shaft-shaped member 36. This prevents the shaft-shaped member 36 from coming off the locking body 40, and prevents further movement of the nozzle body 9 and each piston 21, 31. This position is the stroke end, i.e., the top dead center, of the nozzle body 9 and each piston 21, 31 when each piston 21, 31 is returned to its original position. On the side surface below the locking body 40 in the axial direction, a plurality of opening grooves 43 that serve as a flow path for the liquid contents are formed at regular intervals in the circumferential direction. The inside of the locking body 40 is connected to the inside of the bottle 2 as described below, so that the contents flow from the inside of the locking body 40 through the opening grooves 43 to the liquid chamber 34 on the outside.

At the bottom of the liquid cylinder 19, a check valve is provided that opens when the contents are sucked up from the inside of the bottle 2 into the inside of the liquid chamber 34 and closes when the contents are pushed out from the liquid chamber 34. In the example shown here, the check valve is configured by a ball valve 44, and at the bottom of the liquid cylinder 19, a funnel-shaped valve seat portion 45 whose inner diameter gradually increases toward the top is formed. A ball 46 is arranged so as to contact the tapered surface of the valve seat portion 45 from the upper side of the valve seat portion 45 in the axial direction. Furthermore, a tube 47 is connected to the bottom of the liquid cylinder 19 to introduce the contents filled inside the bottle 2 into the inside of the liquid chamber 34. The tip of the tube 47 extends to the vicinity of the bottom of the bottle 2 (not shown).

Here, the materials constituting each component of the bottle 2 and the pump former 1 described above will be described. Each component of the bottle 2 and the pump former 1 can be manufactured by injection molding a synthetic resin material, for example. Examples of the synthetic resin material include thermoplastic resins, in particular PE (polyethylene), HDPE (high density polyethylene), PP (polypropylene), PET (polyethylene terephthalate), PEN (polyethylene naphthalate), POM (polyoxymethylene), LDPE (low density polyethylene), LLDPE (linear polyethylene), PVC (polyvinyl chloride), PS (polystyrene), ABS (acrylonitrile butadiene styrene), and AS (acrylonitrile styrene). In addition, it is preferable that one of the convex curved surface portion 37B of the valve body portion 37 and the valve seat portion 38 is made of a synthetic resin material that is harder than the other. This is to improve the adhesion between the convex curved surface portion 37B of the valve body portion 37 and the valve seat portion 38, that is, the sealing property of the flow path P, in order to reliably close the flow path P. More preferably, the synthetic resin material constituting the valve body 37 and the convex curved surface portion 37B is harder than the synthetic resin material constituting the valve seat portion 38. This is because the elastic force of the spring 35 presses the convex curved surface portion 37B against the upper surface 38A of the valve seat portion 38 to improve adhesion. For example, it is preferable to form the valve body portion 37 and the convex curved surface portion 37B from PE or HDPE (typical Rockwell hardness value of HDPE: 60-70), and the valve seat portion 38 from PP (typical Rockwell hardness value of PP: 85-110) or POM (typical Rockwell hardness value of POM: 80-120), etc.

Next, the action and effect of the pump former 1 according to the present invention will be described together with its operation. Figure 3 is a diagram showing the process in which the nozzle body 9 in the embodiment of the present invention is pushed toward the bottle 2 side to separate the valve body portion 37 and the valve seat portion 38, (A) of Figure 3 shows the state in which the liquid piston 31 is located at the top dead center, and (B) of Figure 3 shows the state in which the liquid piston 31 is pushed toward the bottle 2 side to separate the valve body portion 37 and the valve seat portion 38. When no force is acting on the nozzle body 9 to push the nozzle body 9 toward the bottle 2 side, the nozzle body 9 is located at the top dead center as shown in Figures 1 and 3A. In this state, the pistons 21 and 31 are pushed upward in the cylinders 18 and 19 (upward in Figures 1 and 3A) by the elastic force of the spring 35. The convex curved surface portion 37B of the valve body portion 37 and the upper surface 38A of the valve seat portion 38 are in close contact with each other due to the elastic force of the spring 35, and communication between the liquid chamber 34 and the mixing chamber 32 and the flow path P is blocked. In addition, since the shaft-shaped member 36 and the convex curved surface portion 37B are made of a synthetic resin material that is harder than the synthetic resin material that makes up the upper surface 38A of the valve seat portion 38, the convex curved surface portion 37B contacts the upper surface 38A in a narrow width close to a line without being crushed. In other words, the convex curved surface portion 37B and the upper surface 38A are in close contact with each other over a narrow area, and the flow path P is reliably sealed.

The engaging portion 41 of the shaft-shaped member 36 is hooked on the hook portion 42 of the locking body 40 and is prevented from coming off the locking body 40. The ball 46 of the ball valve 44 is in contact with the valve seat portion 45 by the contents in the liquid chamber 34 or by the weight of the ball 46, and communication between the liquid chamber 34 and the inside of the bottle 2 is blocked. The first air intake hole 20 formed in the air cylinder 18 is closed by the sliding portion 23 of the air piston 21. Since the air piston 21 does not move in the axial direction, the volume of the air chamber 24 does not change in particular, so the second air intake hole 25 is kept covered by the air intake valve 27, and the air exhaust valve 28 is kept in contact with the flange 33 of the liquid piston 31. In other words, both the air intake valve 27 and the air exhaust valve 28 are closed.

When the nozzle body 9 is slightly pushed toward the bottle 2 from the state shown in FIG. 1 or FIG. 3A, the pistons 21, 31 move slightly toward the bottle 2 under the pushing force. At that time, no force other than the elastic force pressing the engaging portion 41 of the shaft-shaped member 36 against the inner circumferential surface of the locking body 40 and the frictional force between the engaging portion 41 and the inner circumferential surface of the locking body 40 acts on the shaft-shaped member 36. Therefore, when the nozzle body 9 is slightly pushed toward the bottle 2, the shaft-shaped member 36 is fixed to the locking body 40, and the shaft-shaped member 36 maintains a stopped state relative to the cylinders 18, 19. In other words, the shaft-shaped member 36 moves relative to the liquid piston 31. This state in which the shaft-shaped member 36 and the liquid piston 31 move relative to each other occurs until the protrusion 30 and the shaft-shaped member 36 come into contact with each other, and until the liquid piston 31 moves toward the bottle 2 by the amount of the clearance C described above.

Since the air piston 21 is integrally formed with the liquid piston 31, it moves toward the bottle 2 by the same amount as the amount of pressure applied by the liquid piston 31, i.e., the amount of movement in the axial direction. Then, the sliding part 23 of the air piston 21 moves below the first intake hole 20 shown in FIG. 1, and the space above the piston head 22 communicates with the outside of the bottle 2 through the first intake hole 20. In addition, as the pistons 21 and 31 move as described above, the internal volume of the liquid chamber 34 and the internal volume of the air chamber 24 decrease, and the internal pressure of the liquid chamber 34 and the internal pressure of the air chamber 24 increase. Note that when the pump former 1 is unused and is used for the first time, the liquid chamber 34 is not filled with contents and is filled with air. On the other hand, when the pump former 1 has already been used and contents have been discharged from the nozzle 11, the liquid chamber 34 is filled with contents.

When the nozzle body 9 is further pushed toward the bottle 2, the protrusion 30 comes into contact with the valve body 37 of the shaft-shaped member 36, as shown in FIG. 3B. Then, when the nozzle body 9 is further pushed toward the bottle 2 with the protrusion 30 in contact with the valve body 37, the pistons 21, 31 move the shaft-shaped member 36 toward the bottle 2. In other words, the pistons 21, 31 and the shaft-shaped member 36 move together, and the shaft-shaped member 36 moves relative to the cylinders 18, 19. The engagement portion 41 of the shaft-shaped member 36 slides toward the bottle 2 while being pressed against the inner circumferential surface of the locking body 40. Thus, the internal volume of the air chamber 24 is further reduced and its internal pressure is further increased. The air intake valve 27 is pressed against the second intake hole 25 by the internal pressure of the air chamber 24. Meanwhile, the air exhaust valve 28 is separated from the flange 33 of the liquid piston 31. As a result, the air inside the air chamber 24 flows out through the air exhaust valve 28 and flows through the air flow path formed in the fitting portion between the cylindrical portion 29 and the liquid piston 31, and is pushed out into the mixing chamber 32.

Similarly, the internal volume of the liquid chamber 34 is further reduced and its internal pressure is further increased. The ball 46 of the ball valve 44 is pressed against the valve seat 45 by the internal pressure of the liquid chamber 34, and the communication between the liquid chamber 34 and the inside of the bottle 2 is maintained in a blocked state. In addition, in the embodiment of the present invention, as described above, the convex curved surface portion 37B of the valve body portion 37 and the upper surface 38A of the valve seat portion 38 are in line contact or in a state close to that (hereinafter, these contact states are collectively referred to as line contact), and the contact area between the valve body portion 37 and the valve seat portion 38 is reduced compared to the case where the tapered outer peripheral surface 37A of the valve body portion 37 and the upper surface 38A of the valve seat portion 38 are in contact. In other words, the frictional force and engagement force between the convex curved surface portion 37B and the upper surface 38A are reduced, and the force with which the liquid piston 31 pulls down the valve body portion 37 is reduced. Therefore, the internal pressure of the liquid chamber 34 can more easily release the engagement between the convex curved surface portion 37B of the valve body portion 37 and the upper surface 38A of the valve seat portion 38 than ever before, separating the convex curved surface portion 37B from the upper surface 38A. In this way, a gap is formed between the convex curved surface portion 37B of the valve body portion 37 and the upper surface 38A of the valve seat portion 38, connecting the liquid chamber 34 and the mixing chamber 32, and the contents inside the liquid chamber 34 (air in this case) are pushed out of the liquid chamber 34 into the mixing chamber 32 through the gap.

As described above, the liquid piston 31 is pushed down before the valve body 37, and then the protrusion 30 formed on the nozzle body 9 abuts against the upper end of the valve body 37, pushing down the valve body 37 (shaft-shaped member 36). That is, the liquid piston 31 and the shaft-shaped member 36 are both pushed down while maintaining the so-called open state in which the valve body 37 and the valve seat 38 are separated, so that the volume of the liquid chamber 34 is reduced without increasing the internal pressure. When the downward force of the nozzle body 9 is released, the liquid piston 31 is pushed up by the elastic force of the spring 35, so that the valve seat 38 formed at its upper end comes into contact with the valve body 37 formed at the upper end of the shaft-shaped member 36 from below. That is, the liquid piston 31 and the shaft-shaped member 36 are pushed up together in the so-called closed state in which the valve body 37 and the valve seat 38 are in contact, so that the volume of the liquid chamber 34 increases. In this case, the liquid chamber 34 is sealed from the mixing chamber 32 by the valve body 37 and the valve seat 38, so the ball valve 44 opens due to the negative pressure caused by the increase in volume, and the liquid contents in the bottle 2 are sucked up into the liquid chamber 34 via the tube 47.

As described above, when the nozzle body 9 is first pushed down, air is present in the liquid chamber 34, weakening the force resisting the downward pushing of the shaft-shaped member 36. However, in the pump former 1 according to the present invention described above, the frictional force or engagement force between the valve body 37 and the valve seat 38 is small, so that when the nozzle body 9 is pushed down, the valve body 37 and the valve seat 38 immediately separate and open, and in this state, the internal volume of the liquid chamber 34 is reduced. Therefore, the internal volume of the liquid chamber 34 increases or decreases significantly without causing a substantial increase in internal pressure, so that a large amount of contents can be sucked up into the liquid chamber 34 by the initial pumping of the nozzle body 9 and replaced with air. As a result, the number of pumping times required to fill the liquid chamber 34 with liquid contents can be reduced, resulting in a pump former 1 that is highly convenient when first used.

In this way, when the nozzle body 9 is pressed down with the liquid contents sufficiently sucked up into the liquid chamber 34, that is, in the normal use state, the contents pushed out from the liquid chamber 34 are supplied to the mixing chamber 32 with an increased flow rate due to the narrow gap between the convex curved surface portion 37B of the valve body portion 37 and the upper surface 38A of the valve seat portion 38, and the narrow gap between the cylindrical portion 29 and the valve body portion 37. The air pushed out from the air chamber 24 is supplied to the mixing chamber 32 with an increased flow rate due to the narrow air flow path described above. Therefore, in the mixing chamber 32, the air and the liquid contents are mixed and foam is formed. The foam is pushed out from the mixing chamber 32 toward the net holder 14 by the air and contents pushed out from the air chamber 24 and the liquid chamber 34. The foam is made fine and homogenous by passing through the net holder 14, and in that state flows through the flow path P and is discharged to the outside from the nozzle 11.

When each piston 21, 31 moves further toward the bottle 2 and the flange 33 of the liquid piston 31 comes into contact with the boundary between the air cylinder 18 and the liquid cylinder 19, further movement (pushing) of the nozzle body 9 and each piston 21, 31 is prevented. This position is the stroke end on the bottom dead center side of the nozzle body 9 and each piston 21, 31. Then, as the contents are discharged, the pressure inside the air chamber 24 and liquid chamber 34 drops, and when it is balanced with the external pressure, the discharge of the contents stops.

When the force pushing the nozzle body 9 towards the bottle 2 is released, the nozzle body 9 and each piston 21, 31 start to move back towards the mouth 3 of the bottle 2 due to the elastic force of the spring 35. Also, at the point when each piston 21, 31 starts to move back due to the elastic force of the spring 35, no forces other than the elastic force and frictional force are acting on the shaft-shaped member 36. Therefore, the shaft-shaped member 36 is held and fixed by the locking body 40, that is, it is stopped relative to each cylinder 18, 19. The shaft-shaped member 36 moves relative to the liquid piston 31. Therefore, the valve seat portion 38 approaches the valve body portion 37.

As a result of the return movement, the volume of the liquid chamber 34 increases, and the pressure inside the liquid chamber 34 becomes negative, lower than atmospheric pressure. When the valve body 37 and the valve seat 38 are not yet in contact with each other, a gap is formed between them. At least a part of the foamy contents remaining in the flow path P from the nozzle 11 to the liquid chamber 34 is sucked back into the liquid chamber 34 through the gap by the suction force caused by the negative pressure. This operation state in which the foamy contents in the flow path P are sucked back into the liquid chamber 34 continues when the nozzle body 9 and each piston 21, 31 are returned by the elastic force of the spring 35, and until the valve body 37 and the valve seat 38 come into contact with each other and the communication between the liquid chamber 34 and the flow path P is cut off. In addition, the negative pressure causes the ball 46 to separate from the valve seat 45, and the liquid contents filled inside the bottle 2 are sucked up into the liquid chamber 34 through the tube 47.

When the air piston 21 returns to the mouth 3 of the bottle 2 due to the elastic force of the spring 35, the volume of the air chamber 24 increases, and the pressure inside the air chamber 24 decreases. This causes the internal pressure of the air chamber 24 to become negative, lower than atmospheric pressure. The negative pressure presses the air exhaust valve 28 against the flange 33 of the liquid piston 31. Meanwhile, the negative pressure displaces the air intake valve 27 toward the air chamber 24 and separates it from the second intake hole 25. Therefore, the negative pressure causes air outside the bottle 2 to reach the space above the piston head 22 via the air flow path between the guide stem 8 and the outer cylinder 13, and the air flow path between the guide stem 8 and the inner cylinder 12, and is sucked from that space into the air chamber 24 via the second intake hole 25.

When the nozzle body 9 and the pistons 21, 31 are further returned to the mouth 3 of the bottle 2 by the elastic force of the spring 35, specifically, when the pistons 21, 31 are pushed up toward the mouth 3 of the bottle 2 by the same length as the above-mentioned clearance C, the convex curved surface portion 37B of the valve body portion 37 and the upper surface 38A of the valve seat portion 38 come into contact with each other. Since the convex curved surface portion 37B is formed continuously around the entire outer periphery of the valve body portion 37, the contact portion between the convex curved surface portion 37B and the upper surface 38A is a linear contact surface that continues around the entire circumference in the circumferential direction. In other words, the valve body portion 37 and the valve seat portion 38 can be tightly sealed without any gaps in the circumferential direction, so that the flow path P and the liquid chamber 34 can be reliably sealed. In addition, the shaft member 36 and the convex curved surface portion 37B are made of a synthetic resin material that is harder than the synthetic resin material that makes up the upper surface 38A of the valve seat portion 38, so the adhesion between the convex curved surface portion 37B and the upper surface 38A is improved, which also improves the sealing of the flow path P and the liquid chamber 34.

Since communication between the liquid chamber 34 and the flow path P is thus cut off, the suction from the nozzle 11 side due to the negative pressure described above stops. On the other hand, communication between the liquid chamber 34 and the inside of the bottle 2 via the ball valve 44 is not cut off. Therefore, the liquid contents filled inside the bottle 2 are sucked up into the liquid chamber 34 via the tube 47 due to the negative pressure. Also, since communication between the air chamber 24 and the outside is not cut off, the internal volume continues to increase as the air piston 21 returns, and air is sucked into the air chamber 24 due to the negative pressure caused by this increase in internal volume.

Furthermore, when the pistons 21, 31 move back toward the mouth 3 of the bottle 2 due to the elastic force of the spring 35, the engagement portion 41 of the shaft-shaped member 36 finally catches on the hook portion 42, and the return movement of the nozzle body 9 and the pistons 21, 31 stops. Then, when the pressure inside the liquid chamber 34 and the pressure inside the bottle 2 are balanced, the suction of the contents filled inside the bottle 2 stops. Similarly, when the pressure inside the air chamber 24 and the atmospheric pressure are balanced, the suction of air stops. In addition, the first intake hole 20 is blocked by the sliding portion 23. This blocks communication between the inside and outside of the bottle 2, and prevents or suppresses the intrusion of foreign matter into the inside of the bottle 2. That is, the pump former 1 is in the state shown in FIG. 1 or FIG. 3 (A).

In this way, in the pump former 1 according to the embodiment of the present invention, the convex curved surface portion 37B of the valve body portion 37 and the upper surface 38A of the valve seat portion 38 are in continuous line contact around the entire circumference in the circumferential direction, and the contact area is reduced more than ever before. Therefore, even if the liquid chamber 34 is filled with air and the air is compressed by the force pushing the nozzle body 9, that is, the force pushing the nozzle body 9 toward the bottle 2 is consumed in compressing the air, and the force pushing the nozzle body 9 toward the bottle 2 does not act to separate the valve body portion 37 and the valve seat portion 38, the valve body portion 37 and the valve seat portion 38 can be easily separated by increasing the internal pressure of the liquid chamber 34. Therefore, for example, by storing an unused pump former 1 at a high temperature for a certain period of time, the valve body 37 and the valve seat 38 soften, and even if the valve body 37 and the valve seat 38 are engaged with each other by the elastic force of the spring 35, the engagement state can be relatively easily released. In other words, the number of times that the nozzle body 9 is repeatedly pressed in to open the valve mechanism 39 and discharge the contents can be reduced. As a result, when an unused pump former 1 that has been stored at a high temperature for a certain period of time is used for the first time, a problem that makes it difficult to discharge the contents can be prevented or suppressed. In addition, the reliability and marketability of the pump former 1 can be improved. In addition, in the embodiment of the present invention, as described above, no new parts are added, so there is no increase in the number of parts and the associated costs and assembly labor. Therefore, the device has a simple overall configuration and makes it easy to discharge the contents.

Next, we will show examples and comparative examples conducted to verify the effects of this invention.

(Example)
A pump former 1 having the configuration shown in FIG. 1 was prepared. A bottle 2 having the configuration shown in FIG. 1 filled with water as a liquid content was prepared, and the pump former 1 having the above configuration was attached to the mouth 3 of the bottle 2. Then, the number of times the nozzle body 9 was pushed in, i.e., the number of pumpings required to discharge the amount of content assumed in the design, was counted under each test condition in which the temperature of the storage location of the pump former 1 and the storage period were changed. Specifically, the number of pumpings was counted when the pump former 1 was stored at room temperature, i.e., within the range of 25°C ± 2°C, for one week, two weeks, and four weeks. In addition, the number of pumpings was counted when the pump former 1 was stored at 60°C for one week, two weeks, and four weeks as a high temperature condition. Ten pump formers 1 were used for each test condition, and the arithmetic average of the number of pumpings of each pump former 1 and the ease of discharging the content, i.e., the judgment result of whether the product is acceptable or not, are summarized in Table 1 below. The pass/fail judgment of the product was made based on whether the number of pumpings was a predetermined number or less. That is, when the number of pumpings was four or less, the content was easy to discharge and the product was deemed to pass. In Table 1, the pump former 1 that passed the test as a product is marked with "○". When the number of pumpings was 5 to 9, the product was evaluated as the second best product after passing, and marked with "△" in Table 1. Furthermore, when the number of pumpings was 10 or more, the product was deemed to fail. In Table 1, the pump former 1 that failed the test as a product is marked with "×". Note that the number of pumpings that is the criterion for passing the test was set to "4 times" in the above example, but the number of pumpings that users evaluate as easy to discharge the content may vary depending on, for example, the type and quality of the content, the amount of content used each time, etc., so the number of pumpings that is the criterion for passing the test can be set to an appropriate number based on the results of experiments and monitoring.

Comparative Example
The valve body 37 had the same structure as the above-mentioned embodiment except that the convex curved surface 37B was not formed on the tapered outer peripheral surface 37A of the valve body 37, i.e., the tapered outer peripheral surface 37A of the valve body 37 and the upper surface 38A of the valve seat 38 were configured to be in surface contact with each other. The arithmetic average of the number of pumping times of each pump former 1 of the comparative example and the pass/fail judgment results as a product are summarized in Table 1 below.

(evaluation)

In the examples, the number of pumping times was four under each test condition, and all pump formers 1 passed the test as products. This is presumably because, in the pump formers 1 of the examples, even if the valve body portion 37 and the valve seat portion 38 soften and engage with each other due to storage at high temperatures for a long period of time, the convex curved surface portion 37B of the valve body portion 37 and the upper surface 38A of the valve seat portion 38 are in line contact with each other, so that the frictional force between them, i.e., the engagement force, is reduced more than ever before, and the force pulling down the valve body portion 37 (shaft-shaped member 36) is small, and even if the liquid chamber 34 is filled with air, the valve body portion 37 (shaft-shaped member 36) is supported by air pressure and is not pulled down by the liquid piston 31 (valve seat portion 38). That is, a slight increase in the internal pressure in the liquid chamber 34 can release the engagement between the convex curved surface portion 37B of the valve body portion 37 and the upper surface 38A of the valve seat portion 38, separating the valve body portion 37 and the valve seat portion 38, thereby opening the valve.

In contrast, in the comparative example, the number of pumpings was 5 when the storage period was 1 week, 7 when it was 2 weeks, and over 10 when it was 4 weeks, resulting in the product failing under all test conditions. This is presumably because the contact area between the valve body 37 and the valve seat 38 was larger than in the working examples, i.e., the above-mentioned engagement force was larger, so that the valve body 37 (shaft-shaped member 36) and the valve seat 38 (liquid piston 31) were pushed down together, making it difficult to promote the uptake of the liquid contents into the liquid chamber 34.

Note that this invention is not limited to the above-mentioned embodiment, and instead of forming the convex curved surface portion 37B on the valve body portion 37 and contacting the convex curved surface portion 37B with the upper surface 38A of the valve seat portion 38, a convex curved surface portion protruding toward the valve body portion 37 may be formed on the upper surface 38A of the valve seat portion 38 and the convex curved surface portion may be contacted with the tapered outer peripheral surface of the valve body portion 37. Alternatively, in addition to forming the convex curved surface portion 37B on the tapered outer peripheral surface of the valve body portion 37, a convex curved surface portion may be formed on the upper surface 38A of the valve seat portion 38 and the convex curved surface portions may be configured to contact each other. In short, it is sufficient that the contact area between the valve body portion 37 and the valve seat portion 38 is reduced. In addition, the shape of the contact point or contact surface between the convex curved surface portion 37B of the valve body portion 37 and the upper surface 38A of the valve seat portion 38 may be a line that continues in the circumferential direction, as described above, or may be a curved shape that coasts in the axial direction of the shaft-shaped member 36. Furthermore, the convex curved surface portion 37B of the valve body portion 37 may be formed in multiple parts on the valve body portion 37. In short, it is sufficient that the valve body portion 37 and the valve seat portion 38 are configured so that they can close to each other and block the flow path P while reducing their contact area.

1... Pump former (pump-type discharge device)
2: Bottle 3: Mouth 11: Nozzle 19: Liquid cylinder 30: Projection 31: Liquid piston 34: Liquid chamber (one of the interiors partitioned by the cylinder and the piston)
35...Spring (return mechanism)
36 ... shaft-shaped member 37 ... valve body portion (one end portion of the shaft-shaped member)
37B...Convex curved surface part 38...Valve seat part 38A...Top surface 39...Valve mechanism P...Flow path

Claims (3)

a cylinder attached to the mouth of the bottle in a state of communication with the inside of the bottle;
a piston fitted inside the cylinder so as to be capable of reciprocating in an axial direction of the cylinder;
a flow passage formed through the piston in the axial direction;
a nozzle communicating with one open end of the flow path;
one of the interiors partitioned by the cylinder and the piston, the one of the interiors communicating with the other open end of the flow passage;
a valve mechanism having a valve body portion and a valve seat portion that come into close contact with each other to close the flow path when the piston moves in a direction increasing the volume of the one of the interiors, and that separate from each other to open the flow path when the piston moves in a direction decreasing the volume of the one of the interiors;
a return mechanism configured to press the piston in a direction in which the valve body is pressed against the valve seat portion,
The valve body has a tapered outer circumferential surface,
the valve seat portion has a funnel-shaped receiving surface that corresponds to an outer shape of the outer circumferential surface and contacts the outer circumferential surface to close the flow passage,
a pump-type discharge device in which the piston is pushed to separate the valve body from the valve seat and reduce a volume of the one interior, thereby discharging a content filled in the one interior from the nozzle through the flow path ,
A convex curved surface portion having a center of curvature on an opposite side to the receiving surface side is formed continuously around the entire circumference in the circumferential direction of the flow path on the outer circumferential surface,
a contact portion between the convex curved surface portion and the receiving surface forms a continuous line shape over the entire circumference in the circumferential direction of the flow passage,
The valve body portion including the convex curved surface portion is made of a synthetic resin material harder than the synthetic resin material forming the valve seat portion including the receiving surface.
A pump-type discharge device characterized by: 2. The pump-type discharge device according to claim 1,
The valve body is made of high-density polyethylene having a Rockwell hardness of 60 to 70; and
The valve seat is made of polypropylene having a Rockwell hardness of 85 to 110 or polyoxymethylene having a Rockwell hardness of 80 to 120.
A pump-type discharge device characterized by: 3. The pump-type discharge device according to claim 1 or 2 ,
a shaft-shaped member having one end inserted into the flow passage along a central axis of the flow passage and the other end disposed inside the one end, the shaft-shaped member being held so as to be movable relative to the cylinder in the axial direction,
The valve body portion is formed in a tapered shape at the one end of the shaft-shaped member such that an outer diameter gradually increases toward a side opposite to the bottle in the axial direction,
The valve seat portion is formed in the flow passage in a funnel shape having an inner diameter gradually increasing toward a side opposite to the bottle in the axial direction,
The pump type discharge device is characterized in that the convex curved surface portion is formed on the outer circumferential surface.

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